Atmospheric chemistry and pollutants

The research expertise of the group headed by Professor Nelson is in the assessment and control of pollution and on environmental issues associated with energy use. There is a particular emphasis on fine particles, toxic organics and metals from industrial and vehicular sources, trace elements and waste management.

The energy sector is not only the largest contributor to greenhouse gas emissions, but also to air pollutants such as oxides of sulphur and nitrogen, and fine particles with significant health impacts.

Professor Nelson and his team has been interested in developing techniques to determine the contributions of different sources to these pollutants, and in advising on techniques to reduce population exposure to them.

In recent years the team has developed a program of research on mercury, a toxic trace metal with a variety of industrial sources, and long-standing use in industrial processes and commercial products. In 2013, the United Nations agreed on a Convention for mercury management and the team’s research contributed to Australia’s understanding of this issue.

Linking Environmental Pollution to Sources and Causes of Harm

The overriding theme in our work has been to identify sources of contamination and to pinpoint, using multiple lines of evidence, who or what is responsible in order to promote viable solutions. Our evidence-based science has preceded changes in legislation, policy and environmental protection licences along with significant investment from governments and industry to improve environmental outcomes.

Our studies encompass assessing contamination from a range of industrial sources and products: mining, smelting, transport, commercial products and food. In doing this work we have had cause to examine toxic metal contamination and its consequent effect on a range of media: air, ash from wildfires, bees, blood, dust, honey, humans, invertebrates, lichens, soil, sediment, water and wine. In executing our work, we have scrutinised the effects of toxic metal exposures on shifts in rates of aggressive crime (including murder), education and environmental quality.

Iron and steelmaking processes and waste utilisation for energy production

Increased production rates of iron and steel promote economic wealth, yet they impose challenges to sustainable development due to emissions associated with iron and steel-making, and consumption of resources. Research at Macquarie University focusses on understanding of pollutant formation and emissions of particles, trace elements, volatile emissions and persistent organic pollutants during industrial activities. The centre develops tools for assessment of the role of industrial processes on sustainable development based on economic, pollutant emission and resource consumption parameters.

The centre also conducts research on processing of solid wastes and undervalued biomass for production of alternative fuels and renewable energy for power production and industry. The centre has state of the art facilities for assessment of the quality of biomass fuels and their conversion to liquid biofuels, biogas and chemicals. The research primarily focuses on thermal conversion methods for biomass processing.

Organic environmental contaminants in Antarctic ocean waters

Organic geochemistry involves the study of the chemical and isotopic signatures in rocks and sediments, and offers us information about the past. It can be used to reconstruct the nature and timing of important events in the evolution of life. Biomarkers are hydrocarbons that retain the structural information from the original lipids from which they were derived.

Biomarkers and other hydrocarbons in oils, rocks and sediments provide the ability to understand source inputs, subsequent burial and heating history (thermal maturity) and alteration events (such as oil biodegradation).

These skills have been utilised over the last seven years in work funded by the Australian Antarctic Division in two separate projects (AAS3054; 4142), and in a collaboration with Southern Cross University—which has examined the ecotoxicology of fuel oils spilled in Antarctic ocean waters, and the possible role of chemical dispersants for clean-up. Three fuels that are widely used in the Australian Antarctic Territory are Special Antarctic Blend (SAB) diesel, Marine Gas Oil (MGO) and Intermediate Fuel Oil 180 (IFO-180). During this study, we examined the rate of weathering and the path to bioavailability of these fuels to the Antarctic marine biota.

Geochemical investigations of environmental contamination

To determine the extent of metal contamination in environmental materials (water, soils, sediments), the quantification of contaminant concentrations is critical. The isotopic compositions of elements, such as lead, present have also proved valuable for identifying the source of such contamination. Future research into environmental contamination at Macquarie University may benefit from combining the skills and capabilities of the Uranium-Series Research Group (namely in 210Pb research) with the skills and expertise in pollution research. Possible investigations could include assessment of pollution (radioactive accumulation) from coal-fired power plants and zinc processing plants or to better understand pollution histories over the last century through analysis of 210Pb-dated lake sediment cores (e.g., in urban park lakes).

Toxicity and harm from contaminants in aquatic environments

Chemicals and contaminants have been known to enter our waterways, either directly or indirectly, for decades. The extent to which these harm or impact biota and ecosystems, however, has not always been clear. Our research has involved trying to determine what role contaminants play in affecting the health of aquatic systems. Through an evidence-based approach (field chemistry, lab ecotoxicology and field ecology), we explore the ecological risk associated with contamination in the waterways. Particularly, the work involves the use of bio-monitors as sensitive indicators for detecting the presence and extent of contaminants. These studies can affect policy making and management decisions from marine and estuarine to freshwater systems and in both tropical and temperate environments.

Nanocatalysis for air purification and renewable energy production

nocatalysis can play an increasingly important role in the development of renewable energy resources and greener processes. Novel solid catalysts, which are characteristic of cleaner fabrication and higher selectivity, have the most promising potential to replace conventional catalysts in both the energy industry and in environmental remediation. However, a serious challenge remains in improving their activities and selectivities. Recent advances in nanotechnology may move the catalyst development from trial-and-error methods more towards allowing pre-design.